CCL2 and neoplasm: Interestingly, CCR2 expression level in C4-2 siAR cells was much higher when co-cultured with THP-1 scr and siAR (Fig 4A), suggesting that the crosstalk between macrophages and PCa cells confer the robust increase of CCR2 in AR silenced PCa cells, which enable PCa cells to respond to CCL2 in the tumour microenvironment.